1) Field
Embodiments of the present invention pertain to the field of semiconductor processing and, in particular, to methods of water soluble mask formation by dry film lamination.
2) Description of Related Art
In semiconductor wafer processing, integrated circuits are formed on a wafer (also referred to as a substrate) composed of silicon or other semiconductor material. In general, layers of various materials which are either semiconducting, conducting, or insulating are utilized to form the integrated circuits. These materials are doped, deposited, and etched using various well-known processes to form integrated circuits. Each wafer is processed to form a large number of individual regions containing integrated circuits known as dice or dies.
Forming and dicing the integrated circuits may involve formation of a mask layer. Conventionally, a mask layer may be formed by techniques such as spin-coating or screen printing. However, such methods may result in voids or air bubbles due to the high viscosity of the mask material, which may result in a defective mask that fails to provide sufficient protection from subsequent processing.
Other conventional methods of forming a mask involve applying a UV-curable resin sheet directly onto the wafer surface. After subsequent processing (e.g., laser and/or plasma processing), the mask is then cured and a tape is attached to the UV-cured mask to remove the UV-cured mask from the wafer. However, such methods may be disadvantageous because the UV-curable mask material can be difficult to remove from the wafer surface after processing. Additionally, if such a UV-curable mask is applied to an underlying polymeric material (e.g., a dry film underfill layer), subsequent processing may result in melting and re-solidifying of the two layers at the kerf edge, making the layers difficult to separate.